CVODE error when simulating ME-FMU with fmpy 0.3.1

[ranjanan]

When I try to simualate this ME FMU with CVODE, I get this error:

In [8]: fmpy.simulate_fmu(path, start_time = 0.0, stop_time = 5000.0, fmi_type = "ModelExchange", start_values = {"Td0": 343.15, "Tu0": 293.15}, relative_tolerance = 1e-5)
---------------------------------------------------------------------------
Exception                                 Traceback (most recent call last)
_ctypes/callbacks.c in 'calling callback function'()

~\anaconda3\lib\site-packages\fmpy\sundials\__init__.py in f(self, t, y, ydot, user_data)
    125         """ Right-hand-side function """
    126
--> 127         self.set_time(t)
    128
    129         if self.discrete:

~\anaconda3\lib\site-packages\fmpy\fmi2.py in setTime(self, time)
    490
    491     def setTime(self, time):
--> 492         return self.fmi2SetTime(self.component, time)
    493
    494     def setContinuousStates(self, x, nx):

~\anaconda3\lib\site-packages\fmpy\fmi2.py in w(*args)
    213                 # check the status code
    214                 if res > fmi2Warning:
--> 215                     raise Exception("%s failed with status %d." % (fname, res))
    216
    217             return res

Exception: fmi2SetTime failed with status 3.
---------------------------------------------------------------------------
RuntimeError                              Traceback (most recent call last)
<ipython-input-8-784ed9f40178> in <module>
----> 1 fmpy.simulate_fmu(path, start_time = 0.0, stop_time = 5000.0, fmi_type = "ModelExchange", start_values = {"Td0": 343.15, "Tu0": 293.15}, relative_tolerance = 1e-5)

~\anaconda3\lib\site-packages\fmpy\simulation.py in simulate_fmu(filename, validate, start_time, stop_time, solver, step_size, relative_tolerance, output_interval, record_events, fmi_type, start_values, apply_default_start_values, input, output, timeout, debug_logging, visible, logger, fmi_call_logger, step_finished, model_description, fmu_instance, set_input_derivatives, remote_platform)
    785     # simulate_fmu the FMU
    786     if fmi_type == 'ModelExchange':
--> 787         result = simulateME(model_description, fmu, start_time, stop_time, solver, step_size, relative_tolerance, start_values, apply_default_start_values, input, output, output_interval, record_events, timeout, step_finished)
    788     elif fmi_type == 'CoSimulation':
    789         result = simulateCS(model_description, fmu, start_time, stop_time, relative_tolerance, start_values, apply_default_start_values, input, output, output_interval, timeout, step_finished, set_input_derivatives)

~\anaconda3\lib\site-packages\fmpy\simulation.py in simulateME(model_description, fmu, start_time, stop_time, solver_name, step_size, relative_tolerance, start_values, apply_default_start_values, input_signals, output, output_interval, record_events, timeout, step_finished)
   1057         if t_next - time > eps:
   1058             # do one step
-> 1059             state_event, roots_found, time = solver.step(time, t_next)
   1060         else:
   1061             # skip

~\anaconda3\lib\site-packages\fmpy\sundials\__init__.py in step(self, t, tNext)
    169             _assert_cv_success(CVodeGetRootInfo(self.cvode_mem, p_roots_found))
    170         elif flag < 0:
--> 171             raise RuntimeError("CVode error (code %s) in module %s, function %s: %s" % self.error_info)
    172
    173         return flag > 0, roots_found, tret.value

RuntimeError: CVode error (code -8) in module CVODE, function CVode: At t = 4981.9, the right-hand side routine failed in an unrecoverable manner.

I am not sure if this is a problem with the FMU, or I am missing something.

heating.zip

[t-sommer]

The problem seems to be that the FMU raises an error if the solver sets a time that is slightly greater than the stop time in fmi2SetTime() which can happen with variable step solvers.